Sharepoint online list permission based on column value (over 5000 items)

Hi all,

I'd like to set list item permission based on column value but my list might over 5000 items.

If I use unique permission, over 5000 items might slow down the flow.

For example, if column value="done" then users only "can view" the item, otherwise users "can edit".

What I do now is use automate flow, when item and column is modified to "done", then stop sharing this item and grant view access to user. (But if list have more than 5000 items, this won't work..)

Is anyone have better suggestion?

Thank you so much!